Board for manufacturing a BGA and method of manufacturing semiconductor device using thereof

ABSTRACT

By forming a flat member  10  forming a conductive film  11  having substantially same pattern with a second bonding pad  17 , a wiring  18 , and an electrode  19  for taking out , or forming a flat member  30  half-etched through the conductive film  11 , it is possible to manufacture a semiconductor device  23  of BGA structure using a back process of a semiconductor maker.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] THE PRESENT INVENTION RELATES A BOARD FOR MANUFACTURING A BGA(Ball Grid Array) and method for manufacturing a semiconductor deviceusing thereof

[0003] 2. Description of the related Art

[0004] In recent years, use of IC package for portable equipment orsmall, hi-density mounting equipment progresses, and the conventional ICpackage and its concept of mounting are largely changing. These detailsare described in CSP technology, and mounting material and devicesupporting the technology—special issue of DENSHI ZAIRYO (p.22, Set.1998).

[0005]FIG. 15 relates to BGA using a flexible sheet 50 as an inter-poserboard, FIG. 15A is a plan view, and FIG. 15B is a section view cut atA-A line.

[0006] On the flexible sheet 50, a copper foil pattern 51 is bondedthrough adhesive. On the flexible sheet 50, an IC chip 52 is fixed and abonding pat 53 is formed around the IC chip 52 with said copper foil. Asolder-ball connecting pad 55 is formed through a wiring 54 formed inone body with the bonding pad 53, and on the solder-ball connecting pad55, a solder-ball is formed.

[0007] In FIG. 15A, the flexible sheet 50 is shown with a solid line ofoutside, and a rectangle of heavy line is the IC chip 52. As clear fromthe figure, at inside of the bonding pads 53 formed around the IC chip52, the solder-ball connecting pads 55 are formed dispersedly inmatrix-shape.

[0008] At rear side of the solder-ball connecting pads 55, an openingportion 57 is formed by processing the flexible sheet 50, and thesolder-ball 56 is formed through the opening portion 57.

[0009] The above-described flexible sheet 50 is used as a board as sameas ceramic board and printed board, and a member processed most thinlyamong these boards. However the price of the flexible sheet is expensivein comparison with the price of the ceramic board and printed board, andmoreover there is a problem that cost of BGA substantially risesincluding a cost for machining the opening portion 57.

[0010] Thin type and lightweight are desired for a semiconductor devicemounted for portable equipment and also for the above-described BGA.However considering process forming Cu foil pattern, process mountingthe IC chip 52, and process bonding wire 58, the flexible sheet 50 is amember necessarily used for a supporting board, so it is impossible notto use the flexible sheet 50 considering manufacturing process.

[0011] Moreover there is a problem that the Cu foil pattern deforms orpeels off because the Cu foil pattern is bonded with adhesive on theflexible sheet 50. As numbers of pad of the IC chip 52 increases yearand year, making the Cu foil pattern fine is needed for realization withthe BGA. Because of that, bonding area of the wiring 54 and bonding pad53 decreases, thereby the Cu foil pattern deforms or comes off.

[0012] Furthermore there is a problem that manufacturing BGA takes muchtime because a semiconductor maker informs a flexible sheet maker ofdesignated pattern data, the flexible sheet maker manufactures flexiblesheet patterning, and the semiconductor maker purchases the completedflexible sheet. Accordingly it takes for a long time to accomplish asemiconductor device as a product for user. The semiconductor maker cannot deliver said BGA to user in short time.

[0013] There is a problem that radiation of heat of the IC chip 52 isbad because of the flexible sheet 50 interposed between said Cu foilpattern 51 and IC chip 52.

SUMMARY OF THE INVENTION

[0014] The present invention carried out in the view of theabove-mentioned problems is, first, a board for manufacturing BGA,having a first face comprising a flat face and a second face formedfacing to said first face, comprising a flat face. On said second face,a first conductive film having substantially same pattern as a bondingpad provided at periphery of a semiconductor element mounting area, awiring extended to said semiconductor element mounting area in one bodywith the bonding pad, and an electrode for taking out formed in one bodywith the wiring is formed. The above formation solves the problem.

[0015] Second, the invention is a flat member having a first facecomprising a flat face and a second face formed facing to said firstface, comprising a flat face. On said second face, a photo resist havingsubstantially same pattern as a bonding pad formed at periphery ofsemiconductor element mounting area, a wiring extended to saidsemiconductor element mounting area in one body with the bonding pad,and an electrode for taking out formed in one body with the wiring isformed. The above formation solves the problem.

[0016] Third, at area corresponding to said bonding pad, a conductivefilm conductive film is formed, and forming said photo resist so as tocover the film solves the problem.

[0017] By half-etching through conductive film or photo resist formed onthe flat board, a conductive pattern supported with the flat member isformed. Therefore semiconductor makers can manufacture for oneselfconsistently from the flat member to semiconductor device by having anetching facilities.

[0018] As the flat member is used as a supporting board in fixingsemiconductor element, electric connection using bonding wire, andsealing process using insulating resin, conventional flexible sheet as asupporting board is not need. Although the bonding pad is thin andexists in island-shape, and the wiring is arranged in unstable statebecause of its length and thinness, deformation such as bend or peelingis removed because of one body with the flat member.

[0019] By half-etching that pattern of the flat member is not removedfrom face to back by press or etching and the process is stopped on itsway, interval between the conductive patterns can be made narrow so thatfiner pattern can be formed. Further separation of the pad and thewiring is possible by polishing or etching the back of the flat memberafter entirely fixing by sealing with an insulating resin, the patternis arranged in designated position without gap and deformation even inthe state of long wiring taken around.

[0020] In case of half-etching the photo resist as a mask, wire bondingis easily realized at the next process by remaining conductive film atthe bonding pad.

[0021] Forth, the problem is solved by forming a pattern assubstantially same as a guide pin or a guide hole where said guides pinis inserted at side parts of said flat member facing each other so thatdie mounting of said flat member is carried out in high accuracy atmolding.

[0022] Fifth, the problem is solved by said flat member comprises aconductive foil and said conductive film comprises material differentfrom said conductive foil.

[0023] By forming the conductive film, side face of the projection ismade bent and further eaves are formed at the conductive film itself.Therefore a bonding pad and wiring being conductive pattern are buriedin insulating resin with anchor effect.

[0024] Sixth, the invention is a flat member having a first facecomprising a flat face and a second face having a projection formed indesired height and being formed facing to said first face. On saidprojection, a bonding pad provided at periphery of semiconductor elementmounting area, a wiring extended to said semiconductor element mountingarea in one body with the bonding pad, and an electrode for taking outprovided in one body with the wiring are formed. The above formationsolves the problem.

[0025] Seventh, forming a conductive film at surface of said projectionsolves the problem.

[0026] Eighth, providing a conductive film at least at areacorresponding said bonding pad solves the problem

[0027] Ninth, the problem is solved by said flat member comprises aconductive foil and said conductive film comprises material differentfrom said conductive foil.

[0028] In the flat member constructed at the projection, mountingsemiconductor, electric connection to the pad, sealing, and soon arepossible with facilities of later process of semiconductor maker.Therefore it is possible that a flat member is applied by a materialmaker and the semiconductor maker manufactures semiconductor device ofBGA type.

[0029] Further, the flat member can be transferred more easily withoutpositioning shift and can obtain a good bonding ability.

[0030] As the flat member is used as a supporting board in fixingsemiconductor element, electric connection using bonding wire, andsealing process using insulating resin, conventional flexible sheet isremoved. Although the bonding pad exists in island-shape, and isarranged in unstable state, deformation such as bend or peeling isremoved because of one body with the flat member. Although bend orpeeling appears because of long extended wiring, the bonding pad is inone body with the flat member so as to solve the problem.

[0031] Because of, interval between the pads or the conductive patternsis made narrow so that thinner pattern is formed. Further separation ofpad, die pad, and the wiring is possible by polishing or etching theback of the flat member after entirely fixing by sealing with insulatingresin, the pattern is arranged in designated position without gap.

[0032] Tenth, forming a projection of a pattern as substantially same asa guide pin or guides hole where said guide pin is inserted solves theproblem.

[0033] Eleventh, arranging the designated pattern comprising saidprojection in matrix shape at said flat member solves the problem sothat mass production is possible.

[0034] Twelfth, it solves the problem that said flat member comprisesCu, AL, Fe—Ni alloy, layered product of Cu—AL, or layered product ofAl—Cu—Al.

[0035] Thirteenth, it solves the problem that a side face of saidprojection has anchor structure.

[0036] Fourteenth, it solves the problem that said conductive filmprovides eaves at upper face of said projection.

[0037] Fifteenth, according to using said conductive film made of atleast one of Ni, Au, Ag, and Pd, said conductive film has anchor effect,and at the same time wire bonding and die bonding are possible.Sixteenth, the invention is a flat member having a entire flat back facecorresponding to resin sealing area and a front face having a projectionat an area surrounded with an upper die and a contacting area. Theprojection has a bonding pad provided at periphery of a semiconductorelement mounting area, a wiring extended to said semiconductor elementmounting area in one body with the bonding pad, and an electrode fortaking out provided in one body with the wiring. It solves the problemthat at least area surrounded with contacting area with said upper dieconstructs sealing space with said surface and said upper die.

[0038] Seventeenth, the invention is a flat member having a entire flatback face corresponding to resin sealing area and a front face having aprojection. The projection has a bonding pad provided in an areasurrounded with a contacting area to upper die, a wiring extended tosaid semiconductor element mounting area in one body with the bondingpad, and an electrode for taking out provided in one body with thewiring.

[0039] It solves the problem that the invention has process mounting asemiconductor at said semiconductor mounting area and electricallyconnecting said bonding pad and said semiconductor element, processmounting said flat member on a die and filling resin into the spaceconstructed with said flat member and said upper die, and processseparating said projections respectively removing the flat memberexposing at the back face of said resin fill into.

[0040] Eighteenth, the invention is a method for manufacturing asemiconductor device according to claim 17 characterized in that all ofthe back face of said flat member corresponding to said resin-sealingarea contacts a lower die.

[0041] Nineteenth, it solves the problem that contacting area of saidlower die is arranged scattering vacuum suction means.

[0042] Twentieth, said dividing step comprises a step of etching anentire surface of the flat member to a predetermined depth.

[0043] Twenty-First, said dividing step comprises a step of grinding anentire surface of the flat member so as to expose said resin.

[0044] Twenty-Second, said dividing step comprises a step of etching andgrinding the flat member so as to expose said resin.

[0045] As the flat member is formed in sheet shape, the back face of theflat member is contacted in all face of the lower die, moreoverconductive pattern such as pad and so on does not make any burr thereofat the back face of the flat member because that the conductive patternis arrange in said sealing space.

[0046] As mentioned, the invention is constructed with conductivepattern, semiconductor element, and insulating resin sealing these andremoves a flexible sheet so as to realize thin, light semiconductordevice. Moreover by burying a wiring and forming a conductive film onsurface of conductive foil, a bonding pat or a wiring having eaves atface thereof is formed and anchor effect appears so as to realize asemiconductor device of BGA type depressing deformation such as bend,lack, and so on of conductive pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] [FIG. 1]

[0048]FIG. 1 is a view describing the flat member of the invention.

[0049] [FIG. 2]

[0050]FIG. 2 is a view describing the flat member of the invention.

[0051] [FIG. 3]

[0052]FIG. 3 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0053] [FIG. 4]

[0054]FIG. 4 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0055] [FIG. 5]

[0056]FIG. 5 is a view describing the flat member of the invention.

[0057] [FIG. 6]

[0058]FIG. 6 is a view describing the flat member of the invention.

[0059] [FIG. 7]

[0060]FIG. 7 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0061] [FIG. 8]

[0062]FIG. 8 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0063] [FIG. 9]

[0064]FIG. 9 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0065] [FIG. 10]

[0066]FIG. 10 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0067] [FIG. 11]

[0068]FIG. 11 is a view showing the flat member adopted as a lead frame.

[0069] [FIG. 12]

[0070]FIG. 12 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0071] [FIG. 13]

[0072]FIG. 13 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0073] [FIG. 14]

[0074]FIG. 14 is a view describing the method for manufacturing thesemiconductor device adopting the flat member of the invention.

[0075] [FIG. 15]

[0076]FIG. 15 is a view describing the conventional semiconductor deviceof BGA structure.

[0077]10 Flat member

[0078]11 Conductive film

[0079]12 First face

[0080]13 Second face

[0081]14 Semiconductor element mounting area

[0082]15 Semiconductor element

[0083]16 First bonding pad

[0084]17 Second bonding pad

[0085]18 Wiring

[0086]19 Electrode for taking out

[0087]20 Bonding wire

[0088]21 Insulating resin

[0089]22 Conductive pattern

[0090]23 Semiconductor device

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0091] The invention relates a semiconductor device arranged bondingpads at periphery of a semiconductor chip and electrodes for taking outin matrix-shape using wirings of one body with the bonding pads.Although it is generally called BGA that a solder ball is attached atthe electrode for taking out, it is called a semiconductor device of BGAconstruction here including fixing by usual soldering.

First Embodiment

[0092]FIG. 1A shows a flat member which is advanced in effect than BGAso that thinner package is realized, than that of the package using theconventional flexible sheet.

[0093] In the flat member 10, a conductive pattern printed on theconventional flexible sheet in BGA is formed with a conductive film 11.

[0094] That is, the flat member 10 has a first face 12 comprising flatface and a second face 13 comprising flat face provide facing said firstface 12. On said second face 13, a first conductive film 11A assubstantially same pattern as a second bonding pad 17 is formed atperiphery of a semiconductor mounting area 14. The first conductive film11A is provided corresponding to a first bonding pad 16 on asemiconductor element 15 shown in FIG. 3 and is formed in substantiallysame pattern as the second bonding pad 17. A wiring 18 provide in onebody with the above-mentioned second bonding pad 17, a second conductivefilm 11B substantially same pattern with an electrode 19 for taking out,and a third conductive film 11C are formed. These conductive films 11Ato 11C may comprise in same material or not. However for the conductivefilm s 11A to 11C, the material available for etching resist mask isselected as clear in later mentioned method for manufacturing, and forsurface of the conductive film 11A, material in which bonding wire 20comprising Au or Al is in use by ball bonding method or ultrasonicbonding method is selected.

[0095] As clear in description of FIG. 13, material in which brazingfiller metal and conductive paste are fixed is selected for theconductive film 11A in case of using a facedown-type element (SMD) asthe semiconductor element 15.

[0096] On the flat member 10, an etching resist mask MSK such as photoresist and so on may be formed instead of said conductive film 11 asFIG. 1B. In this case, a conductive film 20 is formed at partcorresponding to at least the second bonding pad 17 so that bondingusing bonding wire or facedown bonding is possible, and all patternsincluding the conductive film is covered by photo resist MSK.

[0097] Characteristic of the invention is in said flat member 10. Asclear in later description, the flat member 10 is half-etched throughthe conductive film 11 or photo resist MSK thereof, the semiconductor 15is mounted thereon, and is sealed by insulating resin 21. The flatmember 10 exposing at the back face of the insulating resin 21 isprocessed by etching, grinding or polishing etc. till conductive pad 22comprising the second bonding pad, the wiring 18, and the electrode 19for taking out is separated. By adopting the method for manufacturing,the semiconductor device is constructed by three materials; thesemiconductor element 15, a conductive pattern 22, the insulating resin21 burying the semiconductor element 15 and the conductive pattern 22.The flat member 10 is functioned as a semiconductor device 23 of BGAfinally.

[0098] The biggest characteristic of the structure is that theconductive film 11 or etching-resist mask MSK is formed on surface ofthe flat member 10 so as to half-etch.

[0099] Generally in etching, lateral direction etching advances withadvance of longitudinal direction etching. For example in case ofisotropic etching, this phenomenon appears so that depth of longitudinaldirection etching and length of lateral direction etching aresubstantially same. In anisotropic etching, said lateral directionetching is carried out though length of lateral direction etching isvery shorter than in case of isotropic etching.

[0100] For example in the semiconductor device with BGA structure shownin FIG. 15, in case of forming conductive patterns 53 to 55 on aflexible sheet 50, it is necessary to remove the patterns so as to passthrough from face to back of bonded Cu foil. However interval ofconductive patterns is etched even to lateral direction, interval of theconductive pattern 22 and adjacent conductive pattern thereto can notmade smaller than certain limit value because of correlation withthickness of Cu foil so that forming of fine pattern is difficult. Evenin case of realizing semiconductor device of BGA construction adoptingetching-type lead frame, similar phenomenon appears. Even in case ofremoving the lead frame by press, thickness of the lead frame becomesminimum interval between leads of the lead frame so that fine patternhas limit.

[0101] However by forming the conductive film 11 or the etching-resistmask MSK and then half-etching in depth suitable for fine patternforming, etching quantity of lateral direction is depressed so thatfiner conductive pattern 22 is realized.

[0102] When conductive film 11 such as Ni, Ag, Au, Pd, and so on as aconductive film is formed on the flat member 10 of thickness of 2 oz.(70 82 m) and the film is etched till entirely passing through using amask therefor, interval of the conductive pattern is substantially 70 μmat the narrowest case. However by using the conductive film 11 asetching-resist mask and by etching the flat member 10 till depth of 35μm, interval of the conductive patterns can be processed till depth of35 μm. That is, two times mounting efficiency is realized. In this finepattern, the finer pattern is possible as the shallower depth ofhalf-etching to the flat member 10.

[0103] In the flat member 10 according to the invention, wet etching isdesirable considering etching facilities, mass-productivity, andmanufacturing cost. However wet etching is non-anisotropic and etchingof lateral direction is comparatively great in quantity. Thereforehalf-etching using the conductive film 11 and the etching-resist maskMSK is superior for finer conductive pattern 22.

[0104] In the flat member 10 of the invention, the conductive pattern 22does not slip and bend as long as the flat member 10 is fixed becausethe half-etched conductive pattern 22 is in one body with the flatmember 10. The flat member has characteristic that bonding to the secondbonding pad 17 is stable.

[0105] Although it is need to support the conductive pattern withhanging lead in the semiconductor device with BGA structure forming theabove-mentioned lead frame, it is not need in the invention. Thereforethe conductive pattern 22 is arranged at any position withoutconsidering crossing the hanging lead so that design of the conductivepattern 22 becomes easy.

[0106] It is convenient to provide a guide hole 24 at the time ofmounting the flat member 10 on a die.

[0107] The guide hole 24 may be opened before molding by drill,punching, or etching along the pattern patterned in a round shape atcorresponding position with substantially same shape as a guide pin byconductive film or photo resist. The guide hole may be previouslyopened. Inserting the guide pin of the die into the guide hole 24 makesmolding of high position accuracy possible.

[0108] As above-mentioned, the conductive pattern 22 appears byhalf-etching through the conductive film 11 or the etching-resist maskMSK, and this is possible to adopt as the conventional flexible sheet orthe conventional lead frame.

[0109] A semiconductor maker generally has plants for front process andback process (back-end process) separately, and in the back processmolding adopting the flat member 10, generally etching facilities arenot set up. Therefore the semiconductor maker can manufacture asemiconductor device 23 of BGA construction using the flat member bysetting up film-making facilities of the conductive film 11 and etchingfacilities and by purchasing the flat member 10 where the conductivefilm 11 or the etching-resist mask MSK is formed from a metal materialmaker manufacturing lead frame.

[0110] The conductive pattern 22 may be a shape such as wiring havingsubstantially constant width from an end to other end as shown in FIG.1C. Although the pad 11A and the electrode 11C of FIG. 1A and FIG. 1Bare rectangular and circle respectively, the shape is optional.

[0111] Second Mode for Carrying Out Describing the Flat Member

[0112] The flat member 30 is half-etched through said conductive film 11or etching-resist mask MSK, and a conductive pattern 22 is formed inprojection shape.

[0113] That is, a flat member 30 has a first face 12 comprising a flatface and a second face 13 having a projection 31 formed in desiredheight and being formed facing to said first face 12, and saidprojection 31 comprises a second bonding pad 17 provided at periphery ofsemiconductor element mounting area 14, a wiring 18 of one body with thesecond bonding pad, and an electrode 19 for taking out provided in onebody with the wiring.

[0114] The flat member 30 is substantially as same construction and sameeffect of the flat member 10 described in the first mode for carryingout. Difference is a point that the conductive pattern is half-etched.

[0115] Therefore a half-etching process will be described here. That is,a semiconductor maker, particularly in back process, does not haveplating facilities of a flat member 10 comprising Cu and lithographyfacilities such as etching and so on. Therefore by purchasing the flatmember 30 having the conductive pattern 22 comprising the projectionusing half-etching, the flat member 30 can be handled as same as theconventional lead frame so that it is possible to manufacture thesemiconductor device 23 of BGA construction with existing facilities ofthe back process.

[0116] The conductive pattern 22 comprising the projection can be madeby pressing the flat member 10. In case of the press, it is need to makethe first face 12 flat if necessary by polishing or grinding because thefirst face 12 projects.

[0117] Third Mode for Carrying Out Describing a Method for ManufacturingSemiconductor Device Adopting the Flat Member

[0118] Manufacturing the semiconductor device 23 with BGA structureusing the above-mentioned flat member 10 or 30 is described referringFIG. 1 to FIG. 4. FIG. 2A shows the flat member 10 of FIG. 1Ahalf-etched, and FIG. 2B shows the flat member 10 of FIG. 1Bhalf-etched. FIG. 2C shows the flat member 10 of FIG. 1C half-etched.After FIG. 3, the flat member is described assuming that it ismanufactured like FIG. 1A and FIG. 2A.

[0119] First a flat member 10 is provided. In the flat member 10, thefirst face 12 and the second face 13 are flat, and an etching-resistmask MSK of a conductive film 11 or a photo resist shaping into aconductive pattern conductive pattern 22 are formed on the second face13. In FIG. 1A, the conductive film 11 is formed on all face of theconductive pattern 22, which is hatched with diagonal lines. In FIG. 1B,a photo resist MSK is used instead of the conductive film 11 and coversa conductive film 11A formed at part corresponding to at least a secondbonding pad 17. The photo resist MSK is hatched with dots. (Refer FIG. 1about the above.)

[0120] Next the flat member 10 is half-etched through said conductivefilm 11 or the photo resist MSK. Depth of etching is shallower thanthickness of the flat member 10. The shallower depth of etching, theforming of fine pattern is possible.

[0121] By half-etching, the conductive pattern 22 appears in projectionshape on the second face 13 of the flat member 10 as FIG. 2. The flatmember 10 may be made of Cu material, Al material, Fe—Ni alloy material,layered product of Cu—Al, or layered product of Al—Cu—Al. Particularlylayered product of Al—Cu—Al can prevent bend generating by difference ofcoefficient of thermal expansion.

[0122] For example, by purchasing the flat member 10 of FIG. 1 from aframe maker if a semiconductor maker has etching facilities at the backprocess, and by purchasing the flat member 30 which the conductivepattern thereof is half-etched in projection shape if the semiconductormaker does not have etching facilities, the process can be moved to nextprocess. (Refer FIG. 2 about the above.)

[0123] Next, a semiconductor element 15 is fixed at a semiconductormounting area 14, and a first bonding pad 16 of the semiconductorelement 15 and a second bonding pad 17 are electrically connected. Inthe figure, a bonding wire 20 is used for connecting means because thesemiconductor element 15 is mounted in face-up type. In case of facedowntype mounting, solder bump, brazing material such as solder ball,conductive paste such as Ag and Au, conductive ball, or anisotropicconductive resin is considered for connecting means.

[0124] In this bonding, the second bonding pad 17 is in one body withthe flat member 30, moreover the back face of the flat member 30 isflat. Because of that, the flat member 30 is face-contacted to a tableof a bonding machine. Therefore by entirely fixing the flat member 30 onthe bonding table, without causing the second bonding pad 17 deviated,bonding energy can be transferred to the bonding wire 20 and the secondbonding pad 17 so that connecting strength of the bonding wire 20 isimproved. Fixing of bonding table is possible by providing a plural ofvacuum suction holes V at all the table like FIG. 9 for example.

[0125] For fixing the semiconductor element 15 and the flat member 30,insulating adhesive 32 is used, and considering radiation, filler suchas Si oxide, Al oxide, and so on may be mixed the insulating adhesive32.

[0126] Then an insulating resin 21 is formed so as to cover saidconductive pattern, the semiconductor element 57, and connecting means.

[0127] For example in case of sealing using a die, a guide hole 24 isprovided on the flat board, and a guide pin of the die is inserted intothe hole. Because the first face 12 of the flat member 30 is flat, faceof lower die is formed flat. Any of thermal plasticity andthermohardening is used for the insulating resin 21.

[0128] The molding is realized by transfer molding, injection molding,dipping, and painting realize. As resin material, thermohardening resinsuch as epoxy resin etc. is used for transfer molding, and thermalplasticity resin such as liquid crystal polymer, polyphenylenesulfide,and so on is used for injection molding.

[0129] In the mode for carrying out, thickness of insulating resin 21 isadjusted so that upper part from top portion of the bonding wire 20, isabout 100 μm, is covered. This thickness is possible to make thick orthin considering strength of the semiconductor device 23.

[0130] In filling, position shift of the conductive pattern 22 as longas the flat member 30 does not shift because the conductive pattern isformed in one body with the flat member 30. Fixing the lower die and theback face of the flat member 30 is realized by vacuum suction. Adepressing pin provided at the die may be used.

[0131] As the above, in the insulating resin 21, the conductive pattern22 formed as the projection 31 and the semiconductor element 15 areburied, and the flat member 30 of lower part than the projection 31exposes from the back face of the insulating resin. (Refer FIG. 3 aboutthe above.)

[0132] Next, the flat member 30 exposing at the back face of saidinsulating resin 21 is removed, and the conductive pattern 22 isseparated individually.

[0133] A various methods are considered for the separating process, thatis, the back face may be removed by any of etching and polishing orgrinding. Both of them are available. For example, there is a problemthat scraped chip of the flat member 30 and burr-shape metal extendedthin to outside encroaches on the insulating resin 21 so as to bethinner. Because of that, grinding is stopped before the insulatingresin 21 exposes, after that, by separating the conductive pattern 22 byetching, the conductive pattern is formed without encroaching of metalof the flat member 30 on the insulating resin 21 positioned between theconductive patterns 22. That prevents a short between the conductivepatterns 22 of fine interval.

[0134] In half-etching, dispersion of thickness appears on theinsulating resin 21 between the conductive patterns 22 by dispersion ofetching depth. After separating the conductive patterns 22 individuallyby etching method, Grinding can be conducted so as to be a predeterminedthickness, therefore a package having a certain thickness can be formed.

[0135] In case that a plural of one unit being the semiconductor device23 are formed, there is a dicing process as individual semiconductordevice 23 after the separating process. The dicing line is shown withthick dotted line.

[0136] Although the semiconductor devices are separated individuallyusing the dicing equipment, chocolate breaking, pressing, or cutting ispossible.

[0137] The conductive pattern 22 exposing at the back face may beexposed at part corresponding to an electrode 19 for taking out as FIG.4B. For the exposed electrode 19 for taking out, one of the connectingmeans such as fitting of conductive ball such as solder ball, coveringof conductive paste such as brazing material such as solder orconductive paste such as Ag paste, anisotropic conductive resin isselected.

[0138] In FIG. 4C, etching is carried out through photo resist formed onthe exposed electrode 19 for taking out, and the exposed electrode 19for taking out is made projection shape. A conductive resin R is coveredso that the exposed electrode 19 for taking out exposes.

[0139] By coating the insulting resin R at the back face as FIG. 4B andFIG. 4C, wiring of mounting board side can be passed at the lower layer.(Refer FIG. 4 about the above.) By the above-mentioned method ofmanufacturing, three elements of a plural of conductive patterns 22, thesemiconductor element 15, and insulating resin 21 realizes a light,thin, short, small semiconductor device of BGA structure.

[0140] Next, effect generating by the above-mentioned method formanufacturing.

[0141] First, a flexible sheet used as a supporting board is removedbecause the conductive pattern 22 is half-etched and supported in onebody with the flat member 30.

[0142] Second, making the conductive pattern 22 fine is possible becausethe conductive pattern 22 which is half-etched and has a projection isformed on the flat member 30. Therefore width of the conductive pattern22 and interval between the conductive patterns 22 can be narrow so thatsmaller package in plane size is formed.

[0143] Third, because of construction of said three elements, thesemiconductor device consists of the least necessary elements, anduseless material is removed to the utmost so that a thin typesemiconductor device 23 which is depressed largely in cost is realized.

[0144] Fourth, because the second bonding pad 17, the wiring 18 and theelectrode 19 for taking out are formed in projection by half-etching,and separating individually is carried out after sealing, tie bar andhanging lead(support bar) used for lead frame are not need so thatpattern design becomes easy.

[0145] Although only one semiconductor element is mounted in thesemiconductor device of the BGA structure, a plural of semiconductorelements may be mounted.

Fourth Embodiment

[0146]FIG. 5 shows a flat member 10 where a conductive film 11 forms aconductive pattern 22 as same as the first mode for carrying out. Anetching resist mask such as photo resist may be formed instead of theconductive film 11. In this case, a conductive film is formed at partcorresponding to a bonding pad, and a photo resist pattern is formed soas to cover the conductive film.

[0147] The pattern shaping up the pattern of FIG. 1 is shown in FIG. 5.Concretely, pattern units 34 where conductive pattern surrounded bydotted line is one semiconductor are formed in matrix shape, and diecontacting area 35 is formed in ring shape with designated width assurrounding the pattern units. That is, pattern of FIG. 5 shows theconductive pattern formed in one cavity.

[0148] At inside of the die contacting area 35, alignment marks 36 and37 are provided. A line connecting alignment marks 36A and 37A showsdicing line of lateral direction, and a line connecting alignment marks36B and 37B shows dicing line of longitudinal direction. Each alignmentmark is formed at least one short straight line, and direction of bladeof dicing equipment is adjusted making reference to the straight line.Here alignment mark is provided in the desired interval (margin) so thatthe blade is ground in desired accuracy, and consists of two straightlines.

[0149] Moreover at outside of said die-contacting area 35; a firstpattern 38 and a second pattern 39 for forming a guide hole are formed.The cross of the second pattern 39 is a centering mark when forming theguide hole by drill. A guide hole same shape as the first pattern may beprovided previously without forming the pattern.

[0150] AS above-mentioned, characteristic and effect of the mode forcarrying out are omitted because these are same as the first mode forcarrying out except the line mark of dicing line and the die contactingarea 35.

[0151] Fifth Mode for Carrying Out Describing a Flat Member

[0152] The flat member 30 has a shape shown in FIG. 6, and has aprojection 31 half-etched through the etching-resist mask of theconductive film 11 or the photo resist shown in the fourth mode forcarrying out. A first alignment mark 38 and a second alignment mark 39may be formed in projection shape by half-etching.

[0153] The flat member 30 is handled similarly as the conventional leadframe, SIP, DIP, QIP, and so on for example.

[0154] That is, a flat member 30 has a first face 12 comprising a flatface and a second face 13 having a projection 31 formed in desiredheight and being formed facing to said first face 12, and saidprojection 31 comprises a second bonding pad 17 provided at periphery ofsemiconductor element mounting area, a wiring 18 of one body with thesecond bonding pad 17, and an electrode 19 for taking out 19 provided inone body with the wiring 18.

[0155] The flat member 30 is in the state that each pattern ishalf-etched, and it is possible to fix the semiconductor element, toconnect electrically, and to seal so that manufacturing with existingfacilities of the back process is possible.

[0156] As the effect is described in the first mode for carrying out andthe fourth mode for carrying out, it is omitted here.

[0157] Six Mode for Carrying Out Describing a Method for Manufacturing aSemiconductor Device

[0158] Next, a method for manufacturing the semiconductor device isdescribed referring FIG. 5 to FIG. 11.

[0159] First, a flat member 10 is provided as FIG. 5. Material for theflat member 10 is selected considering adhesion of brazing material,characteristic of bonding and plating characteristic. They are aconductive foil which is Cu as main material, a conductive foil which isAl as main material, a conductive foil of sheet shape comprising alloyof Fe—Ni, layered product of Cu—Al, and layered product of Al—Cu—Al. Onthe surface of the flat member 10, a second bonding pad 17, a wiring 18,an electrode 19 for taking out, a die contacting area 35, alignmentmarks 36 and 37, patterns 38 and 39 are formed by an etching-resist maskof a conductive film 11 or a photo resist.

[0160] It is desired that thickness of the conductive foil used for theflat member 10 is about 10 μm to 300 μm, here Cu foil of 70 μm (2 oz.)is used. However fundamentally the thickness may be more than 300 μm orless than 10 μm. (Refer to FIG. 5 about the above.)

[0161] Next, the flat member 10 is selectively removed except areaproviding the second bonding pad 17, the wiring 18, the electrode 19 fortaking out, the die contacting area 35, the alignment marks 36 and 37,and patterns 38 and 39 so that the area is thinner than thickness of theflat member 10.

[0162] Here the conductive film 11 or the photo resist is used for anetching-resist mask, and said isolation groove 40 is formed shallowerthan thickness of the flat member 10.

[0163] In the method for manufacturing, the flat member is etchednon-anisotropicaly by wet etching or dry etching, and has characteristicthat the side thereof has coarse face and made bend.

[0164] In case of the wet etching, ferric chloride or cupric chloride isgenerally used for etchant, said conductive foil is dipped into theetchant or the etchant is showed.

[0165] Especially just under the conductive film 11 or photo resistbeing etching mask, etching of lateral direction is hard to advance anddeeper part than the etching mask is etched to lateral direction.Because of that, the upper direction of the position goes from one sideof the isolation groove 40, the smaller opening diameter of the openingcorresponding to the position becomes, so that the opening hasreverse-tapered structure having anchor structure. By using showering,etching is advance to depth direction and etching to lateral directionis depressed so that the anchor structure remarkably appears.

[0166] In the case of dry etching, both of anisotropic andnon-anisotropic etchings can be used. Although it is said impossible toremove Cu by reactive ion etching nowadays, Cu is removed by spattering.Depending on the condition of the spattering, both of anisotropic andnon anisotropic etchings are possible.

[0167] Material for the conductive film is Ni, Ag, Au, Pt, or the like.These corrosive resistant conductive film s have characteristic thatthey are used alone for a bonding pad.

[0168] For example, thin Au wire can be bonded to the conductive film ofAg and Au. Ni makes ultrasonic bonding with Al wire possible. Therefore,these conductive film s have a merit that they are used alone for abonding pad.

[0169] Of course here, anisotropic etching may form the projection.(Refer FIG. 6 about the above.)

[0170] Next, there is a process mounting the semiconductor element 15 onthe semiconductor element mounting area 14 as FIG. 7.

[0171] The semiconductor element 15 is a transistor, diode, IC chip, andthe like. CSP of wafer-scale type and SMD (semiconductor element offacedown type) of BGA and the like can be mounted though thickness ofthem becomes thick.

[0172] Here a bare IC chip is fixed by insulating adhesive 32, and afirst bonding pad 16 on the IC chip and a second bonding pad 17 areconnected through a bonding wire 20 fixed by ball bonding usingthermocompression bonding or wedge bonding using ultrasonic wave.

[0173] The bonding pad 17 shown in the figure is in one body with theflat member 30 though the size thereof is very small. Therefore energyof a bonding tool can transfer to the bonding pad 17 so that bondingability is improved. There is a case to pull-cut a bonding wire atcutting the bonding wire after bonding. Because that the second bondingpad 17 is in one body with the flat member 30 in this case, phenomenathat the bonding pad 17 rises is removed and pull-cutting ability isimproved. (Refer FIG. 7 about the above.)

[0174] Moreover there is a process of applying an insulating resin 21 inan isolation groove 40. This is realized by transfer molding, injectionmolding, dipping, or painting. As resin material, thermohardening resinsuch as epoxy resin etc. is used for transfer molding, and thermalplasticity resin such as liquid crystal polymer, polyphenylenesulfide,and so on is used for injection molding.

[0175] In the mode for carrying out, thickness of insulating resin 21 isadjusted so that upper part from top portion of the bonding wire 20,about 100 μm, is covered. This thickness is possible to make thick orthin considering strength of the semiconductor device 23.

[0176] Characteristic of the process is that the flat member 30functions as a supporting board till the insulating resin 21 is coveredand hardened. Although a supporting board of a flexible sheet is need inthe conventional BGA, the invention does not need.

[0177] Moreover, because the insulating resin 21 is filled in theisolation groove 40 having bending structure, anchor effect appears atthis part so that said conductive pattern 22 is hard to peel off fromthe insulating resin 21.

[0178] Potting silicon resin and the like is useful in order to protectconnecting portion the semiconductor chip and the bonding wire forexample before covering the insulating resin 21.

[0179]FIG. 9 shows the molding method. FIG. 9A is a section view showingthe state that the insulating resin 21 is filled into a cavity 101 in adie 100. It is clear that the back face of the flat member 30 contacts alower die 100A and upper die 100B contacts at a die contacting area. Thesymbol V is a vacuum suction hole. FIG. 9B shows the state that the flatmember 30 is mounted on the lower die 100A. Symbol 102 is a guide pinattached at the lower die 100A, and the guide pin appears through aguide hole opened at the flat member 30.

[0180]FIG. 9C is a view describing relation of a cavity 101, a runner103, and a pot 104 formed at the die. As shown in the figure, the die isdesigned so that several cavities 101 are arranged to lateral directionand a lot of semiconductor devices are taken from one frame. Symbol 105shown with dotted line shows arranging area of the flat member, and theflat member 106 like FIG. 11 for example is mounted with handlingsimilar as the conventional lead frame. The flat member 30 as shown inFIG. 6 is formed by using the die where plural cavities and so on aremade in one body. The semiconductor device manufactured with the flatmember itself is small in size, and is possible to take a lot of devicesin one cavity and to mass-product, so as to decrease manufacturing cost.(Refer to FIG. 8 and FIG. 9 about the above.)

[0181] Next, there is a process removing the flat member 30 exposing atthe back face of the insulating resin 21 and separating the conductivepattern 22.

[0182]FIG. 10A is a plan view showing separating line, and FIG. 10Bshows that the back face of the insulating resin 21 and the secondbonding pad 17, or the back face of the insulating resin 21 and wiring18 and the electrode 19 for taking out, are fit. This is possible bygrinding off using polisher or grinder till the isolation groove 40exposes. Only part needing electrical connection may be exposed from aninsulating film such as solder resist and the like.

[0183] In FIG. 10C, a projection 111 is formed at other end 110 of theelectrode 19 for taking out, by stopping the polishing on the way. Thisis possible by forming photo resist at part corresponding to theprojection 111 and by etching part except this. The insulating film R isformed so that the projection 111 exposes. This process can prevent ashort to conductive member of mounting board side passing under thesemiconductor element 15.

[0184] Finally, the semiconductor device completes by arranging themolding member on a dicing table, adjusting position of a bladereferring the alignment marks 36 and 37, and dicing along the line shownwith the dotted line.

[0185] Seventh Mode for Carrying Out Describing a Method forManufacturing a Semiconductor Device

[0186] Next, FIG. 12 to FIG. 14 show mounting a semiconductor element150 of facedown type on a flat member 151 and manufacturing asemiconductor device of BGA structure.

[0187] Although a conductive pattern 22 is extended outer fromsemiconductor element mounting area by using a bonding wire 20, it ispossible to make less or to remove the projection by adopting thefacedown type. Although thickness of the package becomes thick becausethe top of the bonding wire 20 becomes high, thin type is possible byadopting the facedown type.

[0188] For the semiconductor element of facedown type, a solder ball152, or bump of solder or Au instead of the solder ball is used.

[0189] In case of fixing the semiconductor element 150 with brazingmaterial such as solder, it is not need to form the conductive film likethe bonding pad because an electrode for taking out 153 consists of Cuas main material. However it needs for generating anchor effect makingeaves.

[0190] As method for manufacturing is similar as said mode for carryingout, it is described simply.

[0191] A flat member 151 is providing as shown in FIG. 12, the solderball 152 of the semiconductor element 150 is fixed on the flat member151.

[0192] Next, the flat member is sealed using an insulating resin 154 asshown in FIG. 13.

[0193] Finally, the semiconductor device completes by separating theconductive pattern removing the flat member 151 positioning at the backface of the insulating resin 154 and by dicing along the line shown withthe dotted line as shown in FIG. 14.

[0194] A part corresponding to the electrode for taking our may beexposed covering the insulating resin R on the back face of the packageas FIG. 10B and FIG. 10C.

[0195] By covering a conductive film which is small in etching rate onthe flat member and half-etching through the conductive film, eaves andbending structure are realized so as to have anchor effect. This isapplicable for all modes for carrying out.

[0196] The method is suitable because Cu and Ni formed on the Cu areetched at the same time by ferric chloride or cupric chloride and eavesof Ni is formed by difference of etching rate.

[0197] As clear from the above description, the flat member of theinvention has the structure half-etching the conductive pattern throughthe conductive film or the photo resist. Moreover the flat member canconstruct as the conductive pattern by stopping press or etching on theway without removing the flat member from front to back. Theconstruction adopting the half-etching can make interval of theconductive pattern narrow so that the pattern for finer semiconductordevice of BGA construction is possible. As the second bonding pad, thewiring, and the electrode for taking out are constructed in one body,deformation or bend is depressed. Moreover separating the conductivepattern is possible by polishing or etching the back face of the flatmember after fixing entirely sealing the insulating resin so that theconductive pattern can be arranged at the designated position withoutposition shift. Further the wiring necessary for the semiconductordevice of BGA construction can be arranged without any deformation.

[0198] Arranging all of the conductive pattern area in the resin sealingarea can remove burr generating from the conventional lead frame.

[0199] Forming the same pattern as the guide pin can open as the guidehole at sealing with the insulating resin. As the flat member is set onthe guide pin of the die for sealing, resin sealing of high positionaccuracy is possible.

[0200] Constructing the flat member with Cu as main material andconstructing the conductive film with Ni, Ag, Au or Pd can use theconductive film as an etching mask. Further when the flat member ishalf-etched, side thereof provides bending structure and eaves by theconductive film is formed at surface of the conductive pattern, and theflat member has the structure having anchor effect. Therefore removingand bend of the conductive pattern positioning at the back face of theinsulating resin are prevented.

[0201] The semiconductor device manufactured at the flat member consistsof the least necessary elements of the semiconductor element, theconductive pattern, and the insulating resin so that the semiconductordevice is useful for resources. Therefore the semiconductor deviceextremely decreasing cost is realized. As the supporting board such as aflexible board is not used, heat resistance of the supporting board isremoved so that radiation ability is improved. By making thickness offilm of the insulating resin and thickness of the conductive foiloptimum, the small, thin, and light semiconductor is realized.

[0202] Exposing from the insulating resin, the back face of theconductive pattern can instantly connect to outside so that process ofthrough-hole such as the flexible sheet of the conventional structure isnot need.

[0203] The semiconductor device has a structure having flat surfacewhere the surface of the isolation groove and the surface of theconductive pattern are substantially same, and correction of shift ofthe electrode for taking out is extremely easy because the semiconductordevice itself is moved just horizontally even if mounting the narrowpitch GFP on the mounting board.

[0204] Side face of the conductive pattern has bending structure, andeaves are formed at the front face. Therefore it is possible to generateanchor effect and to prevent bend and removing.

[0205] The flat member supports the entire device till the insulatingresin is covered, and at separation and dicing of the conductivepattern, the insulating becomes a supporting board. Therefore thesupporting board described in the prior art is removed, and theinvention has a merit that the device is made low in cost.

1-16. (canceled)
 17. A method of manufacturing a semiconductor devicecomprising steps of: preparing a board comprising a entire flat backface corresponding to a resin sealing area and a front face formed insheet shape having designated thickness from said back face, the frontface forming a projection, the projection having a bonding pad providedat an area surrounded with a contacting area to an upper die, a wiringextended to said semiconductor element mounting area integrated with thebonding pad, and an electrode for taking out provided in one body withthe wiring; mounting each of semiconductor chips at said semiconductorelement mounting area to electrically connect said semiconductor elementto said bonding pad; placing said board on a die; filling resin into thespace constructed with said flat member and said upper die; and dividinginto a plurality of devices so that said projections are separatedrespectively by removing the flat member exposed at the back face ofsaid resin filled into.
 18. A method for manufacturing a semiconductordevice according to claim 17, wherein the entire back face of said flatmember corresponding to said resin-sealing area contacts a lower die.19. A method for manufacturing a semiconductor device according to claim18, wherein that vacuum suction means is arranged separately at acontacting area of said lower
 20. A method for manufacturing asemiconductor device according to claim 17, wherein said dividing stepcomprises a step of etching an entire surface of the flat member to apredetermined depth.
 21. A method for manufacturing a semiconductordevice according to claim 17, wherein said dividing step comprises astep of grinding an entire surface of the flat member so as to exposesaid resin.
 22. A method for manufacturing a semiconductor deviceaccording to claim 17, wherein said dividing step comprises a step ofetching and a step of grinding of the flat member so as to expose saidresin.